It was a mystery that lasted years and finally came to a tragic end. Today, for the first time we're hearing from Christina Adkins' mother. "Christy would never get into a car with somebody she didn'tMore >

It was a mystery that lasted years and finally came to a tragic end. Today, for the first time we're hearing from Christina Adkins' mother.

"Christy would never get into a car with somebody she didn't know so evidently this monster said he would take her to my house," said Debbie Marmol.More >

There's an eerie connection between a man questioned about Christina Adkins and the remains found off I-490. Police say that he was also questioned about a woman found dead off I-490 back in 1994. AccordingMore >

Sex offender on trial for a separate sexual assault is now being questioned about the remains found in the search of Christina Adkins. More >

Justice for Christina Adkins and Pamela Pemberton.

Convicted sex offender Elias Acevedo, Sr. pled guilty Monday to multiple charges; including, aggravated murder, rape and kidnapping. He will spend the rest of his life in prison.

Acevedo, 49, of Cleveland, murdered his neighbor, Pemberton in October of 1994. Her body was found in Cleveland near Clark Field later that month.

Prosecutors say Acevedo persuaded Pemberton to walk with him to a park and killed her.

Acevedo also murdered Christina Adkins. She went missing in January of 1995 from the same W. 25th Street neighborhood where Acevedo lived.

On October 10, 2013, the FBI's Violent Crime Task Force uncovered her remains in a utility vault near the intersections of highways I-71, I-90 and I-490. Prosecutors say Acevedo got Adkins to walk with him during a time when she was upset and killed her in 1995.

Acevedo was convicted of sexual battery in 2003 and subsequently sentenced to three years in prison requiring him to register with local authorities upon his release. Acevedo was arrested earlier this year for failing to report his current address.

The DNA Cold Case Task Force of the Cuyahoga County Prosecutor's Office recently indicted Acevedo as a result of a rape kit recently tested from the 1993 rape of a woman which occurred near the same location where Pemberton's body was found.

Acevedo became a suspect when the FBI's Violent Crime Task Force, which includes special agents from the FBI and detectives from the Cleveland Police Department, Cuyahoga County Sheriff's Office and Cuyahoga County Metropolitan Housing Authority, re-examined the disappearance of other missing women from the Seymour Avenue neighborhood in the aftermath of the Ariel Castro arrest.

In court Monday, Acevedo also pled guilty to raping his pregnant sister-in-law in 1993. The first of his crimes in Cleveland.